英语长句的分析方法：去枝叶，留主干。
1）划出句子中的定语从句和状语从句; 2）划出所有介词短语（位于be动词后的除外）；3）名词性从句看作一个整体,找出句中所有的谓语结构、非谓语结构、介词短语和从句的引导词;4）非谓语动词结构看作一个整体；5）找出全句的主语、谓语和宾语，即句子的主干；6）分析从句的结构和非谓语动词的部结构。
1. But even more important，it was the farthest that scientists had been able to look into the past，for what they were seeing were the patterns and structures that existed 15 billion years ago.结构分析:句子的框架是it was the farthest that…。
但It was…that…在本句中不是强调句型。
it是指上句中所提到的150亿年前形成的巨大云团（a strip of enormous cosmic clouds some 15 billion light-years from earth）;that引导的应是一个定语从句，修饰先行词the farthest。
for引导的是表示原因的分句，分句中还有that引导的定语从句，修饰the patterns and structure。
译文：但更重要的是，这是科学家们所能观测到的有关过去的最为遥远的景象，因为他们看到的是150亿年前宇宙云的形状和结构。
2. Thus it happened that when the new factories that were springing up required labor，tens of thousands of homeless and hungry agricultural workers，with their wives and children，were forced into the cities in search of work，and any work，under any condition，that would keep them alive.结构分析:句子的框架是it happened that…。
it做形式主语，that引导的从句做真正的主语。
主语从句中，又有一个由when引导的时间状语从句，主句为tens of thousands of homeless and hungry agricultural workers…were forced…，时间状语从句中从句主语the new factories又带有一个定语从句that were springing up; that would keep them alive做work的定语从句。
spring up意为“发生，出现，建立”。
译文: 于是就出现了这样的情况:正当新办的工厂纷纷建立，需要劳动力的时候，成千上万无家可归、饥肠辘辘、以农业为生的劳动者携家带口，被迫进入城市;他们要找活干，不管什么活儿，不论什么条件，只要不被饿死就行。
3. As a result of two or three centuries of scientific investigation we have come to believe that nature is understandable in the sense that when we ask her questions by way of appropriate observations and experiments，she will answer truly and reward us with discoveries that endure.结构分析:句子的框架是…we have come to believe that…。
that引导的从句做believe的宾语从句;此从句中有一个that从句作the sense的同位语从句;同位语从句中又套嵌一个由when引导的时间状语从句;此时间状语从句又套嵌一个定语从句that endure，修饰其先行词discoveries。
by way of意为“经由，通过…方法”;reward sb. with意为“以…报答，酬劳”;endure此处应译为“持久，持续”,不要译为“忍受，容忍”。
译文:由于两三个世纪以来的科学研究成果，我们逐渐相信，如果运用合适的观察和实验方法向大自然探究问题，她会真心实意地给我们答复，并且以永垂不朽的发现来报答我们。
从这个意义上来说，大自然是可以认识的。
4. These new observationalcapabilities would result in simply a mass of details were it not for the fact that theoretical understanding has reached the stage at which it is becoming possible to indicate the kind of measurements required for reliable weather forecasting.结构分析:句子的框架是These new observational capabilities would result in simply a mass of details…。
后面紧跟省略了if引导的虚拟条件句were it not for the fact that…，即if it were not for the fact that…;that从句作the fact的同位语从句。
此从句中又套嵌一个定语从句，修饰其先行词the stage; required for reliable weather forecasting为过去分词短语修饰the kind of measurements。
simply译为“只不过，仅仅”，不应译为“简单地”。
译文：理论上的认识已达到了这样一个阶段,即现在已能指出需要哪种测量方式才能可靠地预报天气。
如果做不到这一点，那么上述这些新的观察能力只不过提供了一大堆细节而已。
5. The story of the discovery of what is now generally called the principle of Archimedes，namely that a solid body when immersed in a liquid loses a portion of its weight of the liquidit displaces，has many different versions，of which the following is one.结构分析:句子的框架是The story…has many different versions…。
what is now generally called the principle of Archimedes为名词性从句做介词of的宾语。
namely that a solid body…作the principle of Archimedes的同位语;when immersed in a liquid是省略了主语的过去分词短语，句子补充完整为when the solid body is immersed in a liquid，修饰其主句 a solid body loses a portion of its weight of the liquid…;it displaces是省略了关系代词that的定语从句修饰the liquid，it 代指前面提到的the solid body;同时，of which the following is one又构成先行词versions的定语从句。
displace 意为“排（水）”;version不译为“版本”，此处指“根据个人观点的（对事件等的）说法，看法”;句尾的one代指a version。
译文:当固体浸没到液体中时，固体会失去它所排出的液体的那部分重量，这就是现在通常所谓的阿基米德原理。
有关这一发现的故事说法众多，下面的故事就是其中之一。
6. We assumed that there were forces of attraction between molecules whichvaried rapidly with the distance so that the attraction between molecules that were more than a few ten millionths of a millimeter apart was very small but became considerable when the molecules approached more closely.结构分析:句子的框架是We assumed that there were forces of attraction…。
that引导宾语从句。
此宾语从句中套嵌一个由which引导的定语从句修饰先行词forces of attraction; so that the attraction between molecules…是so that结构引导的结果状语从句;在此状语从句中，除主干结构theattraction…was very small but became considerable…，又有that were more than a few ten-millionths of a millimeter apart做定语从句修饰先行词molecules和when the molecules approached more closely做状语从句，修饰…but became considerable。
considerable译为“相当大（或多的）”。
译文：我们曾经假定，分子之间存在着引力，这种引力随着分子之间距离的不同而有显著的变化，因而，在间距为千万分之几毫米的分子之间的引力是很小的，但是分子靠得很近时，这种引力会变得相当大。
7. This need is enshrined in theconcept of sustainable development，which means that we must，for the benefit of coming generations，leave enough environmental space so that these generations will be able to address their needs and fulfill their aspirations.结构分析:句子的框架是This need is enshrined in the concept of sustainable development…。